Photosynthesis of eight-year-old saplings transplanted into open-top chambers and grown for an additional nine years at different atmospheric CO2 concentrations, with measurements of current-year needles of non-shaded top shoots being made on clear days between 0830 and 1130 hours in the last two years of the study

81%

Zhou et al. (2011)

Photosynthesis of eight-year-old saplings transplanted into open-top chambers and grown for an additional nine years at different atmospheric CO2 concentrations, with measurements of one-year-old needles of non-shaded top shoots being made on clear days between 0830 and 1130 hours in the last two years of the study

41%

Zhou and Han (2005)

Four-year-old saplings grown for four additional years rooted in the ground out-of-doors in open-top chambers